Generally, if an accelerator pedal in an automobile is depressed by a driver, a throttle valve is opened to supply air to an engine, and then, as a quantity of air supplied is increased, a quantity of fuel to be supplied is increased. Thus, the revolutions per minute (rpm) of the engine is abruptly raised, which accelerates the engine.
Recently, with the wide application of an electronic control system through an electronic control unit (ECU) to a variety of types of automobiles, sudden acceleration often happens in the automobiles fitted with an automatic transmission. The electronic control unit is dynamically adopted in a variety of ranges such as engine control for fuel injection, ignition timing and mixture supply, a brake system, a transmission, and the like.
Based upon the quantity of air supplied, an electronic control engine carries out the fuel injection to make an appropriate air-fuel ratio, thereby obtaining desired engine output and further accomplishing fuel saving and exhaust gas reduction. Clear causes of the sudden acceleration occurring by the mounting of the electronic control engine and the electronic control automatic transmission on the automobile have been not reported yet. In most cases, however, erroneous operations (which are generally caused by the generation of electromagnetic waves or the production of noises from a secondary voltage upon ignition) may be made during the signal transmission process between the electronic control unit and the automatic transmission control unit (TCU), and thus, even though the accelerator pedal is not depressed at an initial start-up, or at a drive or rear position, the rpm of the engine is drastically raised to cause the sudden acceleration irrespective of the driver's intention.
Many endeavors to prevent the sudden acceleration of the automobile have been made, but no fundamental solution is suggested yet. As a result, unfortunately, the loss of life and property has been enormously increased.